Six Halo games in one install
Halo: The Master Chief Collection puts six games on PC: Halo: Reach, Halo: Combat Evolved Anniversary, Halo: 2: Anniversary, Halo 3, Halo 3: ODST Campaign, and Halo 4. Together they cover 67 campaign missions, starting with Noble Six in Halo: Reach and running through to the rise of a new enemy in Halo 4. You pick whichever game you want to play first and jump in; nothing forces you to go in order.
Playing the campaign together
Every one of the six games supports co-op, both online and over LAN, so you and your friends can run missions side by side instead of alone. It is the same campaign content either way, just shared with a partner or a full squad. Remote Play is also available for phone, tablet, and TV, which gives you another way to sit down with someone who is not at the same machine.
Multiplayer and Forge
Each game brings its own multiplayer maps, modes, and game types, and the collection totals more than 120 multiplayer maps. Matches can be played competitively player-versus-player, online or on a LAN. Cross-platform multiplayer is supported, so your group does not all need the same setup to end up in the same match.
Forge, Halo's map editor, lets you build maps and set up custom game modes with expanded functionality, a bigger budget, and new objects. Community-made Forge content is a big part of the variety here. Note that Forge is not available in Halo: Combat Evolved Anniversary or Halo 3: ODST.
Settings worth checking before you start
The PC version is built with its own options: mouse and keyboard support with customization, ultrawide support, field-of-view sliders, and more. Performance claims of up to 4K UHD and 60+ FPS depend on your hardware, so use the system requirements as your guide. Full controller support, Steam Achievements, Steam Trading Cards, Steam Workshop, and Family Sharing are all supported.